1. Field of the Invention
The present invention relates to writing data onto a patterned disk of a hard disk drive.
2. Background Information
Hard disk drives contain a plurality of magnetic heads that are coupled to rotating disks. The heads write and read information by magnetizing and sensing the magnetic fields of the disk. The disks are magnetize with a series of transitions. The transitions correspond to digital bits.
Data is stored on concentric tracks that extend radially across the surfaces of the disks. Each track typically contains a plurality of sectors. Each sector may have a number of data fields. Each data field has a sync field that is used to synchronize the reading of data within the field. For example, when reading data the sync field is used as a timing signal to create a read clock. Data is then read from the disk in accordance with the clock. The sync field is typically written with the writing of data.
There have been developed disk media that have patterns of magnetic dots. The dots are constructed from magnetic material and are separated from each other by non-magnetic material. The non-magnetic materials inhibits cross-talk between the dots. The write clock must be very accurate so that the writing of data occurs above a magnetic dot. Using a conventional sync field to synchronize the write clock may result in undesirable jitter and the writing of data that is not aligned with the magnetic dots. Writing the sync field with the data will not necessarily result in the proper alignment of data and dots. The misalignment of writing will produce weak magnetic fields and possible cross-talk with adjacent dots. It would be desirable to provide a disk drive that can accurately write data onto a patterned disk.